The present invention relates to a process and apparatus for preheating coal in which relatively wet coal is passed through one or several flow-through circulation heaters and then collected in a hot coal collection bin prior to being charged into the coke even chambers.
In the prior art installations for preheating coal in circulation heaters a crew is continously necessary to operate the process in spite of the fact that previously individual regulating systems have already been automatized. Thus, for instance the heat carrier gas temperature at the discharge opening of the flow-through circulation tubes has been used to regulate the heat supply. Separate regulation circuits in this case adjust the amount of combustion gas and the amount of combustion air which are coupled to each other by an adjustment of their relative ratio. Through a third regulation circuit the recycling of the vapors to the combustion chamber is adjusted. Changes in the water contents of the charged coal and changes in the throughput will thus receive necessary consideration.
The present invention is concerned with a further improvement of the operation of such preheat installations and its objective is to make a screw necessary only in conveying the coal to the installation and removing it therefrom, that is for a comparatively short period of time. During the remaining time the operating personnel may be used for other purposes, for instance for charging the coke oven battery.